10+ year old plum tree. believe it's Alderman or Pipestone. used to yield nice plums. hasn't for several years. A nearby younger tree is healthy and yields heavily every year.

This year is finally had the start of a good crop but plums are "hollow" and look like the attached pic. Looking for suggestions; ready to cut it down and start over.

Thx in advance to anyone offering advice.

mark in MN